Bacteriological evaluation of goat milk and cheese distributed in the Metropolitan Area of San Jose, Costa Rica.

摘要

A study was conducted to determine the microbiological characteristics of goat's milk and fresh cheese distributed in the metropolitan area of San Jose, Costa Rica and to evaluate its impact in the economic field and as a potential risk for public health. A total of 25 raw goat milk samples, obtained by manual milking from 5 different producers tested in 5 different dates and 15 cheese samples, elaborated with pasteurized milk, commercially available and coming from 3 different producers were analysed. The study included the analysis of spoilage bacteria (total aerobic count and lactic bacterial count), indicators of hygiene (total coliforms), faecal contamination (faecal coliforms), manipulation (Staphylococcus aureus) and pathogens (Listeria monocytogenes and Salmonella spp.). High results were obtained for the total aerobic count and lactic acid bacteria count of the milk and cheese samples, showing a reduced shelf life. Total coliforms, in limits beyond the standards established by the Costa Rican legislation for human consumption of raw milk, were found in 100% of milk samples, as well as faecal coliforms in 76% of them. All cheese samples, except one, were negative for these indicators, suggesting good manufacturing practices. S. aureus counts were low and both Salmonella spp. and L. monocytogenes were not isolated from the samples analysed.